My doctor purchases fillers from Mareli Medical so he can charge less, but are they legitimate?

Thank you for your question. Juvederm Voluma XC is the first facial filler to be approved by the FDA for the non-surgical treatment of the cheeks. If you hear of an offer that is too good to be true, it probably is. Always consult with a board certified facial plastic surgeon that has an experienced injector team with patient testimonials and patient before/after photos.
Best wishes,

Thank you for sharing your question.  Though they may use the original product created by Allergan it is not legal to use fillers obtained internationally.  Unless your injector can prove to you the location and product material is valid I would not advocate receiving treatment.  Hope this helps.

You should research whether the source of the product is an authorized distributor for Allergan's products in the USA, so that the FDA guidelines are followed.